The present invention relates to fluid systems and more particularly to a coupling for a vacuum system.
In a wide variety of applications, a need exists for a quick disconnect-type coupling permitting the user to quickly connect into or disconnect from a source of vacuum. For example, in certain vacuum assist or power assist braking systems, a towed vehicle includes a braking system which is coupled to a vacuum source on the pulling vehicle. Provision is made for connecting the towed vehicle portion of the vacuum system to the pulling vehicle. Since the source of vacuum on the pulling vehicle is typically the intake manifold of an internal combustion engine, it is critical that the coupling not permit air to bleed into the pulling vehicle vacuum system. Leakage might affect the operation of the internal combustion engine.
Vacuum couplings are also used in industrial, dairy and laboratory fields. For example, a source of vacuum may be required at certain workbench areas, such as in electronic manufacture for removal of solder. It would be desirable to provide a central vacuum system including a plurality of outlets positioned at each of the work areas. A user need merely connect into the vacuum system when a source of vacuum is required. Also, in the dairy field, vacuum operated devices are employed. For example, milking machines are available which are vacuum operated. In such systems, it would be desirable to connect selectively the operative portion of the milker to a central source of vacuum at various locations within the milking room or barn.
Heretofore various problems have been experienced in providing a quick disconnect coupling which maintains an adequate seal to prevent leakage of air into the system when connected or disconnected. Also, problems have been experienced with ease of use, reliability in use and ease of manufacture.